Refactor handling of Transfer-Encoding

sdk/lib/io/http_headers.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 class _HttpHeaders implements HttpHeaders {
   _HttpHeaders() : _headers = new Map<String, List<String>>();
 
   List<String> operator[](String name) {
     name = name.toLowerCase();
     return _headers[name];
@@ skipping 59 matching lines @@
   void set contentLength(int contentLength) {
     _checkMutable();
     _contentLength = contentLength;
     if (_contentLength >= 0) {
       _set("content-length", contentLength.toString());
     } else {
       removeAll("content-length");
     }
   }
 
+  bool get chunkedTransferEncoding => _chunkedTransferEncoding;
+
+  void set chunkedTransferEncoding(bool chunkedTransferEncoding) {
+    _checkMutable();
+    _chunkedTransferEncoding = chunkedTransferEncoding;
+    List<String> values = _headers["transfer-encoding"];
+    if (values == null || values[values.length - 1] != "chunked") {
+      // Headers does not specify chunked encoding - add it if set.
+      if (chunkedTransferEncoding) _addValue("transfer-encoding", "chunked");
+    } else {
+      // Headers does specify chunked encoding - remove it if not set.
+      if (!chunkedTransferEncoding) remove("transfer-encoding", "chunked");
+    }
+  }
+
   String get host => _host;
 
   void set host(String host) {
     _checkMutable();
     _host = host;
     _updateHostHeader();
   }
 
   int get port => _port;
 
@@ skipping 78 matching lines @@
     var lowerCaseName = name.toLowerCase();
     // TODO(sgjesse): Add immutable state throw HttpException is immutable.
     if (lowerCaseName == "content-length") {
       if (value is int) {
         contentLength = value;
       } else if (value is String) {
         contentLength = parseInt(value);
       } else {
         throw new HttpException("Unexpected type for header named $name");
       }
+    } else if (lowerCaseName == "transfer-encoding") {
+      if (value == "chunked") {
+        chunkedTransferEncoding = true;
+      } else {
+        _addValue(lowerCaseName, value);
+      }
     } else if (lowerCaseName == "date") {
       if (value is Date) {
         date = value;
       } else if (value is String) {
         _set("date", value);
       } else {
         throw new HttpException("Unexpected type for header named $name");
       }
     } else if (lowerCaseName == "expires") {
       if (value is Date) {
@@ skipping 29 matching lines @@
             _port = parseInt(value.substring(pos + 1));
           } on FormatException catch (e) {
             _port = null;
           }
         }
       }
       _set("host", value);
     } else if (lowerCaseName == "content-type") {
       _set("content-type", value);
     } else {
-      name = lowerCaseName;
-      List<String> values = _headers[name];
-      if (values == null) {
-        values = new List<String>();
-        _headers[name] = values;
-      }
-      if (value is Date) {
-        values.add(_HttpUtils.formatDate(value));
-      } else {
-        values.add(value.toString());
-      }
+        _addValue(lowerCaseName, value);
     }
   }
 
+  void _addValue(String name, Object value) {
+    List<String> values = _headers[name];
+    if (values == null) {
+      values = new List<String>();
+      _headers[name] = values;
+    }
+    if (value is Date) {
+      values.add(_HttpUtils.formatDate(value));
+    } else {
+      values.add(value.toString());
+    }
+  }
+
   void _set(String name, String value) {
     name = name.toLowerCase();
     List<String> values = new List<String>();
     _headers[name] = values;
     values.add(value);
   }
 
   _checkMutable() {
     if (!_mutable) throw new HttpException("HTTP headers are not mutable");
   }
 
   _updateHostHeader() {
     bool defaultPort = _port == null || _port == HttpClient.DEFAULT_HTTP_PORT;
     String portPart = defaultPort ? "" : ":$_port";
     _set("host", "$host$portPart");
   }
 
   _foldHeader(String name) {
     if (name == "set-cookie" ||
         (_noFoldingHeaders != null &&
          _noFoldingHeaders.indexOf(name) != -1)) {
       return false;
     }
     return true;
   }
 
+  void _finalize(String protocolVersion) {
+    // If the content length is not known make sure chunked transfer
+    // encoding is used for HTTP 1.1.
+    if (contentLength < 0 && protocolVersion == "1.1") {
+      chunkedTransferEncoding = true;
+    }
+    // If a Transfer-Encoding header field is present the
+    // Content-Length header MUST NOT be sent (RFC 2616 section 4.4).
+    if (chunkedTransferEncoding &&
+        contentLength >= 0 &&
+        protocolVersion == "1.1") {
+      contentLength = -1;
+    }
+    _mutable = false;
+  }
+
   _write(_HttpConnectionBase connection) {
     final COLONSP = const [_CharCode.COLON, _CharCode.SP];
     final COMMASP = const [_CharCode.COMMA, _CharCode.SP];
     final CRLF = const [_CharCode.CR, _CharCode.LF];
 
     var bufferSize = 16 * 1024;
     var buffer = new Uint8List(bufferSize);
     var bufferPos = 0;
 
     void writeBuffer() {
@@ skipping 60 matching lines @@
       sb.add("\n");
     });
     return sb.toString();
   }
 
   bool _mutable = true;  // Are the headers currently mutable?
   Map<String, List<String>> _headers;
   List<String> _noFoldingHeaders;
 
   int _contentLength = -1;
+  bool _chunkedTransferEncoding = false;
   String _host;
   int _port;
 }
 
 
 class _HeaderValue implements HeaderValue {
   _HeaderValue([String this.value = ""]);
 
   _HeaderValue.fromString(String value, {this.parameterSeparator: ";"}) {
     // Parse the string.
@@ skipping 283 matching lines @@
 
   String name;
   String value;
   Date expires;
   int maxAge;
   String domain;
   String path;
   bool httpOnly = false;
   bool secure = false;
 }